Wyoming Center for Environmental Hydrology and Geophysics

UW-WyCEHG Ecohydrogeophysics (EHG) Course Summer 2013 – Summer 2016

EHG Timeline

Wyoming Center for Environmental Hydrology and Geophysics

2013 – UW & Jackson St. Univ. students participate in Laramie, WY, Late June 2013 – 14 attendees (7 – UW & 7 - JSU), 5 UW Faculty Instructors, 2 UW Staff, Blair- Wallis, and Snowy Range sites. 2014 – UW & Jackson St. Univ. students participate in Jackson, MS, May 2014 - 15 attendees (8 – UW & 7 - JSU), 5 UW Faculty Instructors, 1 JSU Faculty, 3 UW Staff, Collaboration with USACE-Vicksburg at Buck Chute site. 2015 – UW & HBCU students participate in Laramie, WY, May/June 2015, course restricted to 12 – 11 attendees (4 - UW & 7 – HBCU), 1.5 UW Faculty Instructors, 2 Graduate TA’s, 1 UW Staff, Blair-Wallis site. 2016 – UW & HBCU students participate in Laramie, WY, Late July 2016, course restricted to 12 – 13 attendees (11 – UW & 2- HBCU), 1 UW Faculty Instructor, 3 Graduate TA’s, Blair-Wallis site. 2017 – Not Offered

Wyoming Center for Environmental Hydrology and Geophysics

EHG Goals/Learning Outcomes

Wyoming Center for Environmental Hydrology and Geophysics

• In the beginning (2013 & 2014), the course was exclusively available to UW and Jackson State Univ. (MS) students. Students were exposed to the various methods & tools for studying the sciences of Ecology, Botany, Surface Hydrology, and Geophysics. The four sections of the course were independent and little integration between the disciplines was required of the participants.

• At the end (2015 & 2016), the course was opened up to students from any HBCU in the U.S. Additionally, the course objective was to integrate Ecological, Botanical, Hydrological and Geophysical methods to investigate, image and map the surface and subsurface water distribution/movement as it exists and influences the plant life, root zone and upper soils at a predetermined site.

- Simply put, students attempt to quantitatively solve the water balance for the site and evaluate those results within the framework of an hypothetical future scenario/condition at that same site (e.g. fire, road construction, pumping well installation, etc.).

The Water Balance Equation used: ∆S= -ET+ Qnet ∆S is change in storage ET is evapotranspiration Qnet = Qi-Qo

Earth is a closed system which means it has a continuous water cycle.

Water Balance Equation

EHG Instructors & Participants

Wyoming Center for Environmental Hydrology and Geophysics

Instructors: 2013 – Brad Carr, Brent Ewers, Steve Holbrook, Scott Miller, Dave Williams, Liz Nysson, Jordan Hayes, Brady Flinchum 2014 – Brad Carr, Brent Ewers, Ezat Heydari (JSU), Steve Holbrook, Scott Miller, Dave Williams, Liz Nysson, Suman Chitrakar. 2015 – Brad Carr, Dave Williams, Liz Nysson, Suman Chitrakar, Heather Speckman 2016 – Brad Carr, Daniel Beverly, Suman Chitrakar, Jason Mercer, (Liz Nysson). Student Attendees: University of Wyoming – 30 Jackson State University – 17 Howard University - 3 North Carolina A&T - 1 Southern University - 1

Graduate/Undergraduate: Graduate – 14 Undergraduate - 38

Major/Emphasis: Ecology - 4 Botany - 3 Hydrology - 9 Earth Science - 13 Civil Engineering - 14 Computer Sci – 6 Atmospheric Sci – 1 Petroleum Eng. - 1

Wyoming Center for Environmental Hydrology and Geophysics

Field Methods

Geophysics

Objective: Collect and analyze DC Resistivity Data

AGI Super Sting R8/IP/SP Resistivity Meter

-Water table, bedrock depth and structure

-Use pole dipole method

Hydrology

Objective: Figure conductivity, turbidity, and streamflow

HOBO Conductivity Data Logger+Salt Slug

-Two separate sections, 200 grams NaCl each

OTT MF-Pro

-stream discharge for cross section

Photo Credit: www.hobodataloggers.com and Dan Beverly

Ecology

Groundwater wells

- Contained pressure transducer

Sapflow Sensors

- Granier-type sapflow sensors

Meteorological Tower

- Eddy Covariance, vertical wind speeds

- Sonic Anemometers: sensible/latent heat flux

Ecology: Water Isotopes

Collect a variety samples to later extract water isotopes in the Stable Isotope Facility

Surface/Ground Water

Tree Xylem

Soil

Ecology: Vegetation

Pressure Bombing

- Tree samples collected and

- Dried for pressure difference

Tree Core Collection (sapwood)

- Aspen cores, pine cores, willow branches

Results

Hydrology

-1.691926841 ΔS [mm/day]

SALT SLUGDate Q1 Q2 Qnet

7/19/2016 0.007841 0.008883 0.0010419 0.0021 m3/s7/22/2016 0.007291 0.010694 0.0034031 1.80E+11 mm3/day7/26/2016 0.004095 0.005888 0.0017926 270.55 mm/day

MFPRODate Q1 Q2 Qnet

7/19/2016 0.009 0.009 0 -0.0010 m3/s7/22/2016 0.009 0.007 -0.002 -8.64E+10 mm3/day7/26/2016 0.006 0.005 -0.001 -130.12 mm/day

QNet calculated from Salt Slug and MFPro

ΔS from Water table depths

ΔS also calculated from

Geophysics

Use resistivity data from multiple days to obtain a difference in resistance and determine percent change in soil water content

Soil Water Content from Geophysical Data

EHGL1A_INFElectrodes water content at elctrode

Depth 5 16 27 38 50 5 16 27 38 500.5 94.1 245.6 184.9 102 148.8 13.87231 8.12417 9.517912 13.26241 10.7437

1 83.2 80.2 113.9 82.6 106.9 14.85826 15.16573 12.4708 14.91836 12.919851.5 116.1 48.1 169.1 107.7 93 12.33844 20.16947 10.00409 12.86623 13.96358

2 220.7 44.8 273.2 151.3 103.8 8.623269 20.98504 7.655665 10.64433 13.133642.5 465.6 88.8 353.5 267.1 159.6 5.686588 14.32815 6.630843 7.75269 10.33196

3 1012.8 359.5 395.6 267.1 303.7 3.686496 6.568891 6.22751 7.75269 7.2168493.5 1258.9 558 506.2 286.7 609.7 3.265328 5.140469 5.427517 7.452471 4.892608

4 1415.4 1816.1 462.3 344.6 907.2 3.05876 2.661741 5.709191 6.725817 3.9199864.5 1415.4 4137.5 626.7 493.6 907.2 3.05876 1.681607 4.818138 5.504357 3.919986

5 1413 7838.1 1041.4 493.8 1143.5 3.061657 1.177528 3.629683 5.503114 3.445202

Isotope

Ecology

Tower ET= -2.541 mm/day Tree transpiration= -0.925 mm/day

Did we close the water budget equation?

P= 0 mm/day QNet= -130.12 mm/day ET= Tree transpiration + Tower ET

Tree transpiration= -0.925 mm/day Tower ET= -2.541 mm/day ΔS=-1.48 mm/day from resistivity data or -1.69 mm/day from water table data

P= ΔS + ET + QNet

0= -1.48 + (-0.925+ (-2.541))+(-130.12)

0 ≠ -135.006 mm/day

Conclusions

Water Budget Equation was not closed Need more data

Expand study site or change area for better Eddy Covariance Tower data with wind direction

Case Scenario Hypothesis 1: Water storage will increase with less demand

from trees/understory, at least in the case of a moderate fire or moderate thinning.

Hypothesis 2: ET will actually increase after a moderate severity fire.

ario

Hypotheses

Hypothesis 1: The reduction in tree canopy and understory

coverage from a high severity fire will increase water storage because of less water demand from trees.

Hypothesis 2:

Evapotranspiration will decrease after the fire because of the loss of 50 percent of canopy and 75 percent of understory.

Evapotranspiration after high intensity fire

Study site is a mixed forest with predominantly Aspen and Willow tree species, which both recover from fires by resprouting.

After a high intensity fire in a resprouting eucalypt forest, ET has been observed to reduce up to 41%.

ET in a forest burnt at high intensity fire does not recover until around 8-12 years post fire.

Observed a cumulative decrease in ET of around 18% over 5 years, 13% over 10

Reference: “Trends in evapotranspiration and streamflow following wildfire in resprouting eucalypt forests”, Nolan et. Al 2015

Discharge after moderate severity fire Surviving trees have higher rates of transpiration post

fire Mod= ↑ET and ↓Q ET is higher at Mod. sev. site for 0-3 years post fire vs.

high sev. Site Declines in Q due to increased ET following

moderate severity wildfire were of similar magnitude to Q declines driven by a drought that coincided with a fire.

Greater reduction in Q is expected when wildfire occurs during prolonged dry periods

Reference: Nolan et. Al 2015

Conclusions

Water Budget Equation was not closed Need more data

Expand study site or change area for better Eddy Covariance Tower data with wind direction

Case Scenario Hypothesis 1: Water storage will increase with less demand

from trees/understory, at least in the case of a moderate fire or moderate thinning.

Hypothesis 2: ET will actually increase after a moderate severity fire.

Thank you

Wyoming Center for Environmental Hydrology and Geophysics